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Journal of Geographical Sciences 2022年第4期32卷 757-782页

作者： Miguel LEAL Eusébio REIS pedro pinto santos Centre of Geographical Studies and Associated Laboratory TERRA Institute of Geography and Spatial PlanningUniversidade de Lisboa1600-276 LisbonPortugal Forest Research Centre and Associated Laboratory TERRA School of AgricultureUniversidade de LisboaTapada da Ajuda1349-017 LisbonPortugal

Water depths and flow velocities decisively influence the damage caused by flash *** Information System(GIS)is a powerful and useful tool,allowing the spatial analysis of results obtained by hydraulic modelling,namely from the HEC-RAS/HEC-GeoRAS *** GIS spatial analysis performed in this study seeks to explain and quantify the spatial relationships between the stream channel features and flow components during flash flood *** these relationships are generically known,there are few studies exploring this subject in different geographic contexts.A 1D hydraulic model was applied in a small watershed in Portugal,providing good results in the definition of floodable areas,water depths and longitudinal *** direct relationship was found between water depths and velocities in the floodable areas;however,negative strong correlations were found between the two flow components along the stream *** slope,channel and flood width,and roughness prove to be highly relevant on the longitudinal variations of water depths and velocities and on the location of maximum *** peak discharges and return periods(R;)can change the relationships between water depths and velocities at the same *** can be improved with more accurate elevation data for stream channels and floodplains.

关键词： flash floods water depth flow velocity geographic information systems(GIS) spatial analysis

A Novel Approach to Measuring Spatiotemporal Changes in Social Vulnerability at the Local Level in Portugal

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International Journal of Disaster Risk Science 2022年第6期13卷 842-861页

作者： pedro pinto santos JoséLuís Zêzere Susana Pereira Jorge Rocha Alexandre Oliveira Tavares Centre for Geographical Studies Institute of Geography and Spatial PlanningTERRAUniversity of Lisbon(CEG-IGOT-ULisboa)1600-276 LisboaLAPortugal Centre for Social Studies Earth Science DepartmentScience and Technology FacultyUniversity of Coimbra(CES/DCT-FCT-UCoimbra)3000-995 CoimbraPortugal

Social vulnerability,as one of the risk components,partially explains the magnitude of the impacts observed after a *** this study,a spatiotemporally comparable assessment of social vulnerability and its drivers was conducted in Portugal,at the civil parish level,for three census *** first challenging step consisted of the selection of meaningful and consistent variables over *** were normalized using the Adjusted Mazziotta-Pareto Index(AMPI)to obtain comparable adimensional-normalized values.A joint principal component analysis(PCA)was applied,resulting in a robust set of variables,interpretable from the point of view of their self-grouping around vulnerability drivers.A separate PCA for each census was also conducted,which proved to be useful in analyzing changes in the composition and type of drivers,although only the joint PCA allows the monitoring of spatiotemporal changes in social vulnerability scores and drivers from 1991 to 2011.A general improvement in social vulnerability was observed for *** two main drivers are the economic condition(PC1),and aging and depopulation(PC2).The remaining drivers highlighted are uprooting and internal mobility,and daily *** data proved their value in the territorial,social,and demographic characterization of the country,to support medium-and long-term disaster risk reduction measures.

关键词： AMPI normalization Portugal Social vulnerability Spatiotemporal changes

t-SNE:A study on reducing the dimensionality of hyperspectral data for the regression problem of estimating oenological parameters

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Artificial Intelligence in Agriculture 2023年第1期7卷 58-68页

作者： Rui Silva pedro Melo-pinto CITAB-Centre for the Research and Technology of Agro-Environmental and Biological Sciences Inov4Agro-Institute for InnovationCapacity Building and Sustainability of Agri-Food ProductionUniversidade de Trás-os-Montes e Alto DouroQuinta dos PradosVila Real 5000-801Portugal Departamento de Engenharias Escola de Ciências e TecnologiaUniversidade de Trás-os-Montes e Alto DouroQuinta dos PradosVila Real 5000-801Portugal

In recent years there is a growing importance in using machine learning techniques to improve procedures in precision agriculture:in this work we perform a study on models capable of predicting oenological parameters from hyperspectral images of wine grape berries,a specially relevant topic to boost production tasks for ***,we explore the capabilities of a novel technique mostly used for visualization,t-Distributed Stochastic Neighbor Embedding(t-SNE),for reducing the dimensionality of the highly complex hyperspectral data and compare its performance with Principal Component Analysis(PCA)method,which despite the introduction of many nonlinear dimensionality reduction techniques over the years,had achieved the best results for real-world data across several studies in *** we explore the potential of Kernel t-SNE,an extension to the t-SNE method that allows for the usage of the technique in streaming data or online *** results show that,in a direct comparison,t-SNE achieves better metrics than PCA for most of the data sets in this work and that the regressor(Support Vector Regression,SVR)performs better with the t-SNE reduced features as inputs,accomplishing better predictions with lower error *** the results with current literature,our shallow learning model paired with t-SNE achieves either better or on par results than those reported,even competing with more advanced models that use deep learning techniques,which should propel the introduction of t-SNE in more studies that require dimensionality reduction.

关键词： Hyperspectral images Dimensionality reduction Regression T-SNE Support vector machines Wine grape berries

A Simulation of Market-based Non-frequency Ancillary Service Procurement Based on Demand Flexibility

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Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 781-792页

作者： Ricardo Faia Fernando Lezama Tiago pinto pedro Faria Zita Vale José Manuel Terras Susete Albuquerque Research Group on Intelligent Engineering and Computing for Advanced Innovation and Development(GECAD) R.Dr.António Bernardino de Almeida4314249-015PortoPortugal E-REDES Distribuição de Eletricidade S.A.R.Camilo Castelo Branco43LisboaPortugal

This paper proposes a novel approach for the provision of non-frequency ancillary service(AS)by consumers connected to low-voltage distribution *** proposed approach considers an asymmetric pool-based local market for AS negotiation,allowing consumers to set a flexibility quantity and desired price to trade.A case study with 98 consumers illustrates the proposed market-based non-frequency AS provision ***,three different strategies of consumers’participation are implemented and tested in a real low-voltage distribution network with radial *** is shown that consumers can make a profit from the sale of their flexibility while contributing to keeping the network power losses,voltage,and current within pre-defined ***,the results demonstrate the value of AS coming directly from end-users.

关键词： Demand flexibility local electricity market ancillary service low-volatge distribution network

Seamless and non-repetitive 4D texture variation synthesis and real-time rendering for measured optical material behavior

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Computational Visual Media 2019年第2期5卷 161-170页

作者： Martin Ritz Simon Breitfelder pedro santos Arjan Kuijper Dieter W. Fellner Fraunhofer IGD Darmstadt64283Germany TU Darmstadt Darmstadt64289Germany TU Graz Graz8010Austria

We show how to overcome the single weakness of an existing fully automatic system for acquisition of spatially varying optical material behavior of real object surfaces. While the expression of spatially varying material behavior with spherical dependence on incoming light as a 4D texture(an ABTF material model) allows flexible mapping onto arbitrary 3D geometry, with photo-realistic rendering and interaction in real time,this very method of texture-like representation exposes it to common problems of texturing, striking in two disadvantages. Firstly, non-seamless textures create visible artifacts at boundaries. Secondly, even a perfectly seamless texture causes repetition artifacts due to their organised placement in large numbers over a 3D surface. We have solved both problems through our novel texture synthesis method that generates a set of seamless texture variations randomly distributed over the surface at shading time. When compared to regular 2D textures, the inter-dimensional coherence of the 4D ABTF material model poses entirely new challenges to texture synthesis, which includes maintaining the consistency of material behavior throughout the 4D space spanned by the spatial image domain and the angular illumination hemisphere. In addition, we tackle the increased memory consumption caused by the numerous variations through a fitting scheme specifically designed to reconstruct the most prominent effects captured in the material model.

关键词： optical material behavior reflectance modeling 4D texture synthesis texturing

Temporal and spatial differences in human activities performed in Urban Green Spaces of Vilnius(Lithuania)

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Geography and Sustainability 2024年第2期5卷 302-317页

作者： Luís Valença pinto Carla Sofia santos Ferreira Paulo Pereira Research Centre for Natural Resources Environment and Society(CERNAS) Polytechnic Institute of CoimbraBencanta3045-601 CoimbraPortugal Environmental Management Laboratory Mykolas Romeris UniversityVilniusLithuania Polytechnic Institute of Coimbra Applied Research InstituteRua da MisericórdiaLagar dos Cortiços-S.Martinho do Bispo3045-093 CoimbraPortugal

Urban green spaces(UGS)are relevant to city well-being,as recognized by the United Nations’Sustainable Development Goals(SDGs).However,few studies have studied the temporal use of *** work assessed the seasonal,weekly,and daily use of three urban green spaces(Vingis Park,Bernardino Garden,and Jomantas Park)in Vilnius(Lithuania).The study is based on an on-site observation-based survey,which recorded users’characteristics,activities,and weather conditions during summer and *** results showed that UGS’s seasonal,weekly,and daily use differed according to park and users’*** with a higher diversity of facilities had a high seasonal difference in the number of observed *** numbers were higher in the summer for activities with children,social activities,sports,and water activities than in the *** Park had the lowest variability in user *** variables were linked to changes in users’*** precipitation and lower temperature were associated with reducing the number of users and the diversity of registered *** of the stationary activities were observed during *** diversity of the observed activities was associated with the available facilities rather than the park *** distribution of stationary activities was spatially correlated with facility/equipment(benches,playgrounds,sports,and fitness equipment)and proximity to water *** results of this study are relevant for UGS design,planning,and management.

关键词： Urban parks Seasonal differences Temporal use Time of day Spatial distribution of UGS users

Effect of climate and altitude on plant community composition and richness in Brazilian inselbergs

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Journal of Mountain Science 2020年第8期17卷 1931-1941页

作者： Herval Vieira pinto-JUNIOR pedro Manuel VILLA Luis Fernando Tavares de MENEZES Miriam Cristina Alvarez PEREIRA Universidade Federal de Vigosa Department of Plant BiologyLaboratory of Ecology and Evolution of Plants36570-900Vicosa-MGBrazil Universidade Federal de Vigosa Department of Forest EngineeringLaboratory of Forest Restoration36570-900Vicosa-MGBrazil Universidade Federal do Espirito Santo Department of Agrarian and Biological SciencesLaboratory of Ecology of Restinga and Mata Atlantica29932-900Sao Mateus-ESBrazil Universidade Federal do Espirito Santo Department of Biology29500-000Alegre-ESBrazil

Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical *** evaluate the influence of altitude and climatic variables related to temperature and precipitation on plant community composition and species richness on Brazilian *** assume as a premise that both climate and altitude would induce changes on plant community composition and species richness at the local *** used plant inventory data from 370 sampling units across four inselberg sites in the Atlantic Forest of Espírito Santo State,south-eastern *** tested the univariate and multivariate effects of altitude and climate variables on community composition and species richness with multiple *** in species richness between inselbergs were evaluated using sample-based data to estimate rarefaction and extrapolation *** addition,differences in species composition and taxonomic beta diversity were examined via novel frequency-based metrics.A contrasting climate pattern was observed between the inselberg sites,with south sites being wet compared to the dry conditions found in northern *** richness by rarefaction showed a similar pattern within regional sites;however,there were marked differences between *** richness and beta diversity showed significant differences among sites,with higher values in southern sites than in northern *** a multi-model comparison between inselberg sites,altitude significantly influenced community composition and species richness and explained more variance than climate *** finding suggested that climate could act to some extent on these tropical inselbergs;however,altitude was a better predictor of plant community composition and species richness at the local level.

关键词： Atlantic Forest Biome Beta diversity Abiotic filtering Climate models Environmental filtering Latitudinal gradient

Static-based early-damage detection using symbolic data analysis and unsupervised learning methods

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Frontiers of Structural and Civil Engineering 2015年第1期9卷 1-16页

作者： Joao pedro santos Christian CREMONA Andre D. ORCESI Paulo SILVEIRA Luis CALADO Department of Structures Av. Brasil 101 Lisbon 1700-066 Portugal Technical Center for Bridge Engineering CEREMA B.P. 214 Provins Cedex 77487 France Materials and Structures Department IFSTTAR University Paris-Est 14-20 Boulevard Newton Champs sur Marne Marne la Vallee Cedex2 F-77447 France Department of Civil Engineering Technical University Lisbon Avenida Rovisco Pais Lisbon 1096 Portugal

A large amount of researches and studies have been recently performed by applying statistical and machine learning techniques for vibration-based damage detection. However, the global character inherent to the limited number of modal properties issued from operational modal analysis may be not appropriate for early-damage, which has generally a local character. The present paper aims at detecting this type of damage by using static SHM data and by assuming that early-damage produces dead load redistribution. To achieve this objective a data driven strategy is proposed, consisting of the combination of advanced statistical and machine learning methods such as principal component analysis, symbolic data analysis and cluster analysis. From this analysis it was observed that, under the noise levels measured on site, the proposed strategy is able to automatically detect stiffness reduction in stay cables reaching at least 1%.

关键词： structural health monitoring early-damage detection principal component analysis symbolic data symbolic dissimilarity measures cluster analysis numerical model damage simulations

High Order of Accuracy for Poisson Equation Obtained by Grouping of Repeated Richardson Extrapolation with Fourth Order Schemes

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Computer Modeling in Engineering & Sciences 2021年第8期128卷 699-715页

作者： Luciano Pereira da Silva Bruno Benato Rutyna Aline Roberta santos Righi Marcio Augusto Villela pinto Graduate Program in Numerical Methods in Engineering Federal University of ParanaCuritiba81531-980Brazil Graduate Program in Space Sciences and Technologies Aeronautics Institute of TechnologySao Jose dos Campos12228-900Brazil Department of Mechanical Engineering Federal University of ParanaCuritiba81531-980Brazil

In this article,we improve the order of precision of the two-dimensional Poisson equation by combining extrapolation techniques with high order *** high order solutions obtained traditionally generate non-sparse matrices and the calculation time is very *** can obtain sparse matrices by applying compact *** this article,we compare compact and exponential finite difference schemes of fourth *** numerical solutions are calculated in quadruple precision(Real*16 or extended precision)in FORTRAN language,and iteratively obtained until reaching the round-off error magnitude around 1.0E−*** procedure is performed to ensure that there is no iteration *** Repeated Richardson Extrapolation(RRE)method combines numerical solutions in different grids,determining higher orders of *** main contribution of this work is based on a process that initializes with fourth order solutions combining with RRE in order to find solutions of sixth,eighth,and tenth order of *** multigrid Full Approximation Scheme(FAS)is also applied to accelerate the convergence and obtain the numerical solutions on the fine grids.

关键词： Tenth order accuracy RRE compact scheme exponential scheme multigrid finite difference

A discussion about the limitations of the Eurocode’s high-speed load model for railway bridges

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Railway Engineering Science 2024年第2期32卷 211-228页

作者： Gonçalo Ferreira pedro Montenegro JoséRui pinto António Abel Henriques Rui Calçada CONSTRUCT-LESE Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias4200-465 PortoPortugal CONSTRUCT-LABEST Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias4200-465 PortoPortugal

High-speed railway bridges are subjected to normative limitations concerning maximum permissible deck *** the design of these structures,the European norm EN 1991-2 introduces the high-speed load model(HSLM)—a set of point loads intended to include the effects of existing high-speed ***,the evolution of current trains and the recent development of new load models motivate a discussion regarding the limits of validity of the *** this study,a large number of randomly generated load models of articulated,conventional,and regular trains are tested and compared with the envelope of HSLM *** each type of train,two sets of 100,000 load models are considered:one abiding by the limits of the EN 1991-2 and another considering wider *** comparison is achieved using both a bridge-independent metric(train signatures)and dynamic analyses on a case study bridge(the Canelas bridge of the Portuguese Railway Network).For the latter,a methodology to decrease the computational cost of moving loads analysis is *** show that some theoretical load models constructed within the stipulated limits of the norm can lead to effects not covered by the *** is especially noted in conventional trains,where there is a relation with larger distances between centres of adjacent vehicle bogies.

关键词： High-speed load model Dynamic analysis High-speed railways Train signature Railway bridges Deck acceleration